Inventories (principally using the LIFO method) are comprised of the following:
December 31,
(Millions of dollars)
2016
2015
Raw materials
$
2,102
$
2,467
Work-in-process
1,719
1,857
Finished goods
4,576
5,122
Supplies
217
254
Total inventories
$
8,614
$
9,700